Surgery equipment holding device

ABSTRACT

A surgery equipment holding device including a holder for holding surgical equipment, a bar connected to the holder, a brake which operatively engages the bar for stopping movement of the bar, and a pair of switches for switching being an active state and an inactive state of the brake. The surgery equipment holding device is characterized in the operation thereof at the time of disengaging the fixation state, and exhibits excellent operability.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. Ser. No. 10/114,539filed on Apr. 2, 2002, now U.S. Pat. No. 7,160,308 which claims thebenefit of Japanese Application No. 2001-152922 filed on May 22, 2001,the contents of each of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a surgery equipment holding device forholding surgery equipment, and particularly relates to a surgeryequipment holding device with excellent operability, that ischaracterized in the operation thereof at the time of disengaging thefixation state.

2. Description of the Related Art

In recent years, surgery equipment holding devices which hold surgeryequipment instead of surgeons have come into use. Such surgery equipmentholding devices are configured having an arm portion serving as changeholding means, joints serving as fixation maintaining means disposed atthe arm portion, and switches serving as fixation disengaginginstructing means.

Appropriately operating the switches changes the state of the jointsbetween disengaged and fixed states. That is to say, moving the surgeryequipment to a desired position and fixing it there can be performed byoperating switches.

For example, DE 295 11 899 UI and Japanese Patent No. 2,843,507 haveconfigurations wherein the fixed state of the joints is disengaged by asurgeon operating switches.

Also, the second embodiment disclosed in Japanese Unexamined PatentApplication Publication No. 7-227398 discloses a surgery equipmentholding device wherein the balance of an endoscope is maintained even inthe event that the fixed state of the joints disposed on the arm portionis disengaged, by means of the surgery equipment holding devicecomprising an electromagnetic brake and counter balance.

Further, with the device for holding surgery equipment disclosed in EP 0293 760 B1, two mode switches are provided. One mode switch is a firstmode to immediately disengage the fixed state of the joints. The othermode switch is a second mode exhibiting a holding force wherein thejoints disposed on the arm portion can hold an endoscope and alsowherein the surgeon can move the endoscope.

However, with the surgery equipment holding devices disclosed in theaforementioned DE 295 11 899 UI and the aforementioned Japanese PatentNo. 2,843,507, at the point that the surgeon operates switches to movethe endoscope, the fixed state of the joints is immediately disengaged.

Accordingly, in the event that the surgeon operates switches to move thefield of view of the endoscope, the fixed state is immediatelydisengaged, which suddenly places the weight of the endoscope and thearm portion onto the hand of the surgeon holding the endoscope. Thesurgeon is unable to respond to such sudden change of load and the tipof the endoscope undesirably moves. Accordingly, the surgeon loses thefield of view prior to disengaging the fixation, and thus must performthe task of regaining the field of view. This has been a problem whichhas led to lowered surgery efficiency.

Also, with the surgery equipment holding device disclosed in theaforementioned Japanese Unexamined Patent Application Publication No.7-227398, in the event that the surgeon operates switches, the fixedstate of the joints is immediately disengaged. This suddenly places theforce of the hand of the surgeon on the arm portion, and the sameproblem as described above occurs since the arm portion which isbalanced is moved thereby.

Further, with the surgery equipment holding device disclosed in EP 0 293760 B1, in the event that the surgeon specifies the second mode, theendoscope is held with a predetermined force, which takes care of theproblem wherein the tip of the endoscope moves. However, with caseswherein the endoscope must be moved frequently during the surgery, suchas with brain surgery for example, using this device causes the problemthat the surgeon must move the endoscope against the resistance of thefixing force every time. This places a load on the hand and arm of thesurgeon. Also, operations for moving the endoscope minute distancesagainst the resistance of the fixing force have been difficult.

On the other hand, in the event that the surgeon specifies the firstmode, the fixing force of the joints is immediately disengaged, so thesame problem as described above occurs.

Also, the configurations of placement positions of the switches of theconventional devices for holding surgery equipment do not take intoconsideration the axial direction of insertion of the endoscope. Inother words, the configuration has been such that the relative positionthereof changes according to the placement of the arm.

Accordingly, the surgeon cannot instantaneously know the direction whichthe endoscope is facing. Accordingly, there has been a problem in thatit takes time to move the endoscope in the intended direction.

Also, equipment used for brain surgery and the like generally has a formwherein the surgeon pinches the equipment between his/her thumb andindex finger. However, with conventional devices for holding surgeryequipment, the grasping direction and insertion operating direction havediffered with such equipment. In addition, unlike such equipment, theswitches are in one location, so the surgeon tends not to be at easewith operating the surgery equipment holding device.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide asurgery equipment holding device wherein, at the time of operatingswitches to disengage the fixed state, a sudden load is prevented frombeing placed on the hand of the surgeon holding the surgical equipmentor on the surgical equipment being held in the surgeon's hand.

It is another object of the present invention to provide a surgeryequipment holding device with excellent operability.

To this end, a surgery equipment holding device according to the presentinvention comprises: a holder for holding surgical equipment; a barconnected to the holder; a brake which operatively engages the bar forstopping movement of the bar; and a switch for switching being an activestate and an inactive state of the brake.

The above and other objects, features and advantages of the inventionwill become more clearly understood from the following descriptionreferring to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 through 5 relate to a first embodiment of the present invention,wherein:

FIG. 1 is a diagram illustrating a schematic configuration of a surgeryequipment holding device;

FIG. 2 is a diagram illustrating the state of the surgery equipmentholding device holding a therapeutic device in the equipment holdingportion thereof;

FIG. 3 is a diagram explaining the structure of a fluid brake;

FIG. 4A is a diagram explaining the structure of a fluid control unit;

FIG. 4B is a diagram explaining the configuration of the fluid controlunit provided with a variable diaphragm;

FIG. 5 is a block diagram explaining the primary configuration of thesurgery equipment holding device;

FIG. 6 is a block diagram explaining the configuration of the surgeryequipment holding device according to a modification of the firstembodiment;

FIG. 7 is a block diagram explaining another configuration of thesurgery equipment holding device according to a second embodiment of thepresent invention;

FIGS. 8 and 9 relate to a third embodiment of the present invention,wherein:

FIG. 8 is a diagram explaining another configuration of the surgeryequipment holding device;

FIG. 9 is a block diagram explaining the configuration of the surgeryequipment holding device;

FIGS. 10 through 12B relate to a fourth embodiment of the presentinvention, wherein:

FIG. 10 is a diagram explaining yet another configuration of the surgeryequipment holding device;

FIG. 11 is a cross-sectional diagram explaining the configuration of thegrasping portion;

FIG. 12A is a block diagram explaining yet another configuration of thesurgery equipment holding device;

FIG. 12B is a block diagram explaining yet another configuration of thesurgery equipment holding device;

FIGS. 13 through 14B relate to a fifth embodiment of the presentinvention, wherein:

FIG. 13 is a diagram explaining the principal configuration of thesurgery equipment holding device;

FIG. 14A is a block diagram explaining the position where the controlcircuit is disposed;

FIG. 14B is a diagram explaining the position where the control circuitis disposed; and

FIG. 15 is a diagram explaining a modification of the fifth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment of the present invention will now be described withreference to FIGS. 1 through 5.

As shown in FIG. 1, a surgery equipment holding device according to thepresent invention has, for example, an endoscope 1 as a device forobserving the part of the body which is the object of the surgery. Atelevision camera head 2 having a CCD for example for picking up opticalimages of observed parts is mounted on an eyepiece 1 a of the endoscope1 having an insertion portion 1 d capable of intracavital insertion.Images signals of the optical images converted by the unshown CCDprovided to the television camera head 2 are generated as video signalsat a controller 3 which is a video signals processing device. The videosignals generated at the controller 3 are output to a monitor 4. Thus,endoscope images of the part observed are displayed on the screen of themonitor 4.

The endoscope 1 is held by a holding arm 5 serving as change holdingmeans. The holding arm 5 is of a configuration which allows the positionand direction of the endoscope 1 being held to be changed.

Disposed on the tip side of the holding arm 5 which is one edge thereofare an equipment holding portion 6 for holding the endoscope 1, and agrasping portion 7 for the surgeon to grasp. On the other hand, anattaching portion 9 is provided to the other end of the holding arm 5,for being fixed to a surgery table 8, for example.

While the present embodiment is described with the endoscope 1 as anexample of the surgery equipment held by the equipment holding portion6, therapeutic devices such as forceps 100, a type of surgicalequipment, may be held by the equipment holding portion 6, as shown inFIG. 2.

The holding arm 5 has a first arm 10 a, a second arm 10 b, and a thirdarm 10 c, serially linked from the attaching portion 9 side. A first rod11 a and a second rod 11 b are disposed between the first arm 10 a andthe second arm 10 b, and between the second arm 10 b and the third arm10 c, respectively.

A first fluid brake 12 a, a second fluid brake 12 b, a third fluid brake12 c, and a fourth fluid brake 12 d, serving as fixation maintainingmeans are disposed at the joint portions between the first arm 10 a andfirst rod 11 a, second arm 10 b and the first rod 11 a, the second arm10 b and second rod 11 b, and third arm 10 c and the second rod 11 b,respectively.

A first switch 13 a and second switch 13 b are provided as a pair, asfixation disengaging instructing means, to the grasping portion 7. Thefirst switch 13 a and the second switch 13 b are disposed so as to be inplanar symmetrical positional relation across a plane 1 c, the hatchedportion in the figure, which contains the insertion axis 1 b of theendoscope 1.

The first switch 13 a and second switch 13 b are electrically connectedto a fluid control unit 14 which is a fixation force control means. Afirst fluid hose 16 a and second fluid hose 16 b, which are channels fora pressured fluid, extend from the fluid control unit 14.

The end of the second fluid hose 16 b is coupled to a fluid pressuresource 15 for supplying compressed air or compressed nitrogen gas,commonplace in surgery rooms. On the other hand, the end of the firstfluid hose 16 a branches into several parts at the base end side. Thebranched ends each couple with the first fluid brake 12 a, second fluidbrake 12 b, third fluid brake 12 c, and fourth fluid brake 12 d.

The first switch 13 a and second switch 13 b are known push-buttonswitches for example, and are contact switches having contacts. Thefirst switch 13 a and second switch 13 b are electrically seriallyconnected to a later-described control circuit 35 provided within thefluid control unit 14.

Now, the structure of the first fluid brake 12 a will be described withreference to FIG. 3.

Note that the structure of the second fluid brake 12 b, third fluidbrake 12 c, and fourth fluid brake 12 d, are the same as that of thefirst fluid brake 12 a. Accordingly, the structure of the first fluidbrake 12 a alone will be described, and that of the second fluid brake12 b, third fluid brake 12 c, and fourth fluid brake 12 d will beomitted.

As shown in the figure, the first arm 10 a of the first fluid brake 12 ahas a hollow structure. Disposed within the first arm 10 a are agenerally-spherically formed ball end 21 formed on the end of the rod 11a with a radius R, and a pressing portion 20 of a predetermined form.

An abutting portion 17, formed of the spherical face having a radius R,is provided at the tip of the inside of the first arm 10 a. Accordingly,the ball end 21 comes into planar contact with this abutting portion 17.Note that the point A in the figure represent the center of the abuttingportion 17 and the ball end 21.

The pressing portion 20 comprises a pressing member 22, a shaft 23, anda piston 24. The pressing member 22 has a pressing face for pressing theball end 21. The shaft 23 is integrally provided on the base face of thepressing member 22. The piston 24 is integrally provided on the baseface of the shaft 23.

A protrusion 18 is formed in the inside of the first arm 10 a. A spring25 is disposed between this protrusion 18 and the pressing member 22, ina compressed state. Accordingly, the pressing force of the spring 25acts to press the pressing member 22. Consequently, the pressing member22 pressing the ball end 21 causes the ball end 21 and the abuttingportion 17 to be pressed one against another, so as to be in a fixed andheld state.

As shown in FIG. 3, a first o-ring 27 a for maintaining an airtightstate is disposed between the protrusion 18 and the shaft 23. Also, asecond o-ring 27 b for maintaining an airtight state is disposed betweenthe inner circumference of the piston 24 and the first arm 10 a.Providing these o-rings 27 a and 27 b makes the space defined by thefirst arm 10 a and shaft 23 and piston 24 to be an airtight space 28. Aninlet port 29 communicating with the airtight space 28 is formed in thepiston 24. The end of the hose 16 a is communicably connected to thisinlet port 29.

The structure of the fluid control unit 14 will be described withreference to FIGS. 4A and 5.

As shown in these figures, an electromagnetic valve 30, serving as knownmeans for switching channels, is disposed in the fluid control unit 14.The electromagnetic valve 30 has three ports 31 a, 31 b, and 31 c,serving as the input channel, discharge channel, and functioningchannel, for the pressured fluid. A known solenoid 32 configured of acoil 33 and shaft 34 are provided to the electromagnetic valve 30. Thecoil 33 of the solenoid 32 is electrically connected to the first switch13 a and second switch 13 b via the control circuit 35.

A valve 36 is integrally provided on the tip side of the shaft 34. Inthe event that this valve 36 is at the position indicated by solid linesin the figure, the port 31 b and the port 31 a are in a communicatingstate. On the other hand, in the event that the valve 36 is at theposition indicated by dotted lines in the figure, the port 31 b and theport 31 c are in a communicating state. That is to say, theconfiguration is such that the channels are switched by the valve 36moving.

A spring 37 is disposed between the shaft 34 and a housing 38. The valve36 is placed at the position indicated by the solid lines due to thepressing force of this spring 37.

A known diaphragm 39, capable of narrowing down the cross-sectional areaof the fluid tube, is disposed between the port 31 c of theelectromagnetic valve 30 and an inlet port 40. The inlet port 40 iscoupled to a fluid pressure source 15 via a hose 16 b, such that theconnection is airtight, while allowing the fluid to pass through.

The hose 16 a is coupled to the port 31 b. The base portion of the hose16 a is connected to the inlet port 40 communicating with the airtightspace 28 formed at each of the first fluid brake 12 a, second fluidbrake 12 b, third fluid brake 12 c, and fourth fluid brake 12 d, suchthat the connection is airtight, while allowing the fluid to passthrough.

The port 31 a is opened to the atmosphere via an vent tube 41.

The cross-sectional area Qx (m²) of the fluid channel of the diaphragm39 and the cross-sectional area Qy (m²) of the vent tube 41 are set in arelation such thatQx<<Qyholds.

Now, the operation of the surgery equipment holding device configuredthus will be described.

First, the fixation holding state of the surgery equipment holdingdevice will be described.

At the time of this fixation holding state, the first switch 13 a andthe second switch 13 b are unpressed, and the valve 36 is situated atthe position indicated by the solid line in the figure by the pressingforce of the spring 37. Accordingly, the port 31 b and the port 31 a arein a communicating state.

Thus, the vent tube 41 and the airtight space 28 are communicating viathe port 31 a, port 31 b, and hose 16 a. In other words, the airtightspace 28 is released to the atmosphere.

Consequently, the pressing portions 20 within the first fluid brake 12a, second fluid brake 12 b, third fluid brake 12 c, and fourth fluidbrake 12 d are pressed against the abutting portion 17 side by thepressing force of the spring 25. As a result, the ball end 21 is pressedand fixed against the abutting portion 17 by a fixing force of F (N), bythe pressing member 22 making up the pressing portion 20.

That is to say, the endoscope 1 is fixed and held in a constantposition, due to the rod 11 a and the rod 11 b being in a fixed state.

Now, in this fixation state, the pressured fluid in the fluid pressuresource 15 is in a pressured and filled state near to around the port 31c, via the hose 16 b, inlet port 40, and diaphragm 39.

Next, the operation for causing the fixed and held endoscope 1 to movewill be described.

In the event of moving the endoscope 1, the fixation holding state ofthe first fluid brake 12 a, second fluid brake 12 b, third fluid brake12 c, and fourth fluid brake 12 d is disengaged. To this end, thesurgeon presses and operates the first switch 13 a and the second switch13 b disposed on the grasping portion 7.

Note that the relative positional relation between the first switch 13 aand the second switch 13 b disposed on the grasping portion 7 and theendoscope 1 is always the same, regardless of the attitude of theholding arm 5.

Also, as described above, the first switch 13 a and the second switch 13b are disposed so as to be in plane symmetrical positional relationacross a plane 1 c which contains the insertion axis 1 b of theendoscope 1. Accordingly, the surgeon can operate while grasping thegrasping portion 7 and pinching the first switch 13 a and the secondswitch 13 b with the thumb and index finger.

The surgeon simultaneously pressing and operating the first switch 13 aand the second switch 13 b brings the electromagnetic valve 30 toaction. The action of the electromagnetic valve 30 causes the valve 36to move against the pressing force of the spring 37 due to a solenoid 32from the position indicated by solid lines to the position indicated bydotted lines. Thus, the port 31 b and the port 31 c are in acommunicating state. This causes the pressured fluid which had beenfilled in a pressurized state up to the port 31 c to flow into theairtight space 28 via the port 31 b and the hose 16 a. That is to say,the pressured fluid continues to pass through the diaphragm 39 formedwith a cross-sectional area Qx (m²) into the airtight space 28, until anisopiestic state is attained between the airtight space 28 and the fluidpressure source 15.

Once the pressure within the airtight space 28 begins to rise, reactionforce is generated at the piston 24 against the pressing force of thespring 25 pressing the pressing member 22. That is, the pressing forcepressing the ball end 21 of the pressing portion 20 gradually drops.Finally, the pressed fixation state of the ball end 21 which had beenpressed and fixed against the abutting portion 17 by the pressingportion 20, is disengaged.

This allows the ball ends 21 disposed within the first fluid brake 12 a,second fluid brake 12 b, third fluid brake 12 c, and fourth fluid brake12 d to rotate on the center point A. That is to say, the first rod 11 aand the second rod 11 b become movable. Thus, the surgeon can move theendoscope 1 to a desired position.

Next, description will be made regarding a case wherein the surgeonfixes the endoscope 1 again.

Upon moving the endoscope 1 to the desired position, the surgeonreleases his/her fingers from the first switch 13 a and the secondswitch 13 b to fix and hold the position of the endoscope 1. This causesthe valve 36 of the electromagnetic valve 30 to return from the positionindicated by dotted lines to the position indicated by solid lines, dueto the pressing force of the spring 37. Thus, the port 31 a and the port31 b communicate.

At this time, the pressured fluid filling the airtight space 28immediately is released into the atmosphere through the vent tube 41formed with a cross-sectional area Qy (m²), via the ports 31 b and 31 a.Consequently, the reaction force decreases, the pressing portion 20 ispressed by the pressing force of the spring 25, and the ball end 21 ispressed and fixed against the abutting portion 17. Thus, the endoscope 1is in a fixed and held state at the position to which the surgeon hasmoved it.

That is to say, at the time of disengaging the fixation, the pressuredfluid passes through the diaphragm 39 formed with a cross-sectional areaQx (m²). Conversely, at the time of fixing, the pressured fluid passesthrough the vent tube 41 formed with a cross-sectional area Qy (m²).

Now, the relation of Qx<<Qy has been set between Qx and Qy, so theamount of fluid passing through these channels per unit time is in thesame relation as with the relation of cross-sectional area. That is, thedifference set here in the amount of fluid passing through causes thedisengaging action of the surgery equipment holding device to be carriedout gradually. On the other hand, the fixing action of the surgeryequipment holding device is performed rapidly. Accordingly, there is nosudden placing of a load on the hand of the surgeon at the time ofdisengaging the fixation, while the endoscope is speedily fixed at thetime of fixation.

In this way, the cross-sectional area of the channels through which thepressured fluid passes at the time of disengaging fixation and at thetime of fixing is set such that the cross-sectional area of the channelthrough which the pressured fluid passes at the time of disengagingfixation is smaller than the cross-sectional area of the channel throughwhich the pressured fluid passes at the time of fixing, so that on onehand, while the surgeon can disengage the fixed state of the endoscopewithout any sudden placing of holding load on the hand of the surgeon,on the other hand, the endoscope can be speedily set in a fixed state atthe time of fixing.

Thus, at the time of moving the surgery equipment, the surgeon cansmoothly move the surgery equipment to the desired position withoutlosing sight of the part of the body to be observed or treated.Accordingly, the working time can be reduced, the fatigue of the surgeoncan be lightened, and surgery efficiency improves greatly.

Also, control of fixation disengagement and fixing can be performedusing the pressured fluid of a fluid pressure source normally installedin surgery rooms, so there is no need to prepare a new fluid pressuresource or install complicated control circuits, and accordinglyease-of-use is facilitated.

Further, a small and simple structure can be realized, by adoptingsimple electrical contact switches as the switches. In addition, byelectrically connecting a pair of switches serially to the controlcircuit instruction signals can be surely prevented from being output inthe event that only one switch is operated.

Also, the relative positional relation between the switches and theplane containing the axis of the endoscope is constant, thereby solvingthe problem of the surgeon having to confirm the position each time whenmoving the surgery equipment held by the surgery equipment holdingdevice to a desired position and fixing the surgery equipment thereat,so time efficiency in the surgery can be achieved as well.

Note that in the present embodiment, the fluid pressure source 15 isdescribed as a configuration using compressed air or compressed nitrogengas or the like installed in the surgery room, but the pressured fluidis not restricted to these, and oil, viscous fluids, etc., capable ofbeing compressed, may be used.

Also, with the present embodiment, the configuration indicated uses anelectromagnetic valve 30 for switching channels, but the switching ofthe channels is not restricted to an electromagnetic valve; rather, anychannel switching means capable of switching channels according toinstructions from the first switch 13 a and second switch 13 b issufficient, and another example will be described later.

Next, a modification of the first embodiment will be described withreference to FIG. 4B.

As shown in the figure, with the present embodiment, the diaphragm 39provided to the inlet port 40 in FIG. 4A has been changed to a variablediaphragm 39 a. The variable diaphragm 39 a allows the operator to setthe fluid influx to a desired amount. That is to say, this variablediaphragm 39 a allows the amount of influx of the fluid to the airtightspace 28 to be suitably adjusted in increments of time. Consequently,the surgeon can set the time which elapses till the brakes aredisengaged to a desired value, and can smoothly move the surgeryequipment to the object part. Thus, according to the present embodiment,the operability of the device improves, and fatigue of the surgeon isalleviated.

Further, in FIG. 4B, a variable diaphragm 39 b is provided to the venttube 41 as well, so that the operator can set the amount of fluiddischarged to a desired amount. That is to say, this variable diaphragm39 b allows the amount of fluid discharged from the airtight space 28 tobe suitably adjusted in increments of time. Consequently, the surgeoncan set the time which elapses till the brakes are active, to a desiredvalue.

Now, it is generally held to be true that the time required for thebrakes to become active should be as short as possible. However, it isalso undeniable that there are timings which are intuitively acceptableand unacceptable according to individuals. In regard to this, thepresent embodiment allows the time for the fluid to flow into theairtight space 28 via the variable diaphragm 39 a to be adjusted, andthe variable diaphragm 39 b can be adjusted to achieve matching with thecapacity of the airtight space 28 itself, so a surgery equipment holdingdevice capable of reducing fatigue, which is suitably operable and meetsthe preferences of each of multiple surgeons, can be provided.

Note that in the event that the only object of the surgeon is tosmoothly move the surgery equipment to the object part, all that isnecessary is to set the time until the brakes are disengaged. In otherwords, the object of the present embodiment can be achieved simply byadding the variable diaphragm 39 a in order to adjust the timing ofdisengaging the brakes to the preference of the surgeon.

Next, a modification of the first embodiment will be described withreference to FIG. 6.

As shown in the figure, with the present embodiment, the configurationof the fluid control unit 14 serving as the fixing force control meanshas been changed as follows.

With the fluid control unit 14A according to the present embodiment, adirectional diaphragm unit 42 is disposed between the port 31 b of theelectromagnetic valve 30 and the hose 16 a. This directional diaphragmunit 42 comprises a diaphragm 43 and a check valve 44 which allows thefluid to only flow in the one direction indicated by the arrow.

That is, the check valve 44 is provided such that only the fluid fromthe airtight spaces 28 formed in the first fluid brake 12 a, secondfluid brake 12 b, third fluid brake 12 c, and fourth fluid brake 12 d,passes.

Also, the cross-sectional area Qx1 of the diaphragm 43 and thecross-sectional area Qy1 of the check valve 44 are set in a relationsuch thatQx1<<Qy1holds. That is to say, the relation is set such that the cross-sectionalarea of the channel through which the pressured fluid passes at the timeof disengaging fixation is smaller than the cross-sectional area of thechannel through which the pressured fluid passes at the time of fixing.

The surgeon simultaneously pressing and operating the first switch 13 aand the second switch 13 b in order to disengage the fixed state of theendoscope 1 brings the electromagnetic valve 30 to action, and the port31 b and the port 31 c communicate. This causes the pressured fluid topass through the port 31 c and port 31 b and then flow into thedirectional diaphragm unit 42. The pressured fluid which flows into thedirectional diaphragm unit 42 then passes through the diaphragm 48 andenters the airtight space 28 to act in the same manner as with the firstembodiment.

On the other hand, upon the surgeon releasing his/her fingers from thefirst switch 13 a and the second switch 13 b to fix and hold theposition of the endoscope 1, the pressured fluid filling the airtightspace 28 immediately is released into the atmosphere, as with the firstembodiment, primarily through the check valve 44.

That is to say, at the time of flowing into the airtight space 28, thepressured fluid passes through the diaphragm 43 formed with across-sectional area Qx1. On the other hand, at the time of flowing outof the airtight space 28, the pressured fluid passes through the checkvalve 44 formed with a cross-sectional area Qy1.

Now, the relation of Qx1<<Qy1 has been set between Qx1 and Qy1, so aswith the first embodiment, causes the disengaging action of the surgeryequipment holding device to be carried out gradually, and the fixingaction of the surgery equipment holding device to be performed rapidly.That is to say, operations and advantages similar to those of the firstembodiment can be obtained at the time of disengaging the fixation andat the time of fixing.

In this way, a simple configuration that is easy to use can be realizedby using a known diaphragm and check valve in the directional diaphragmunit.

A second embodiment of the present invention will be described withreference to FIG. 7.

Note that with the present embodiment, components common to the firstembodiment will be denoted with the same reference numerals anddescription thereof will be omitted.

As shown in the figure, the fluid pressure source 15 according to thepresent embodiment is coupled to the port 31 c of the electromagneticvalve 30 via the hose 16 b. The port 31 b of the electromagnetic valve30, and an inlet port 29 a communicating with the airtight spaces 28formed at each of the first fluid brake 12 a, second fluid brake 12 b,third fluid brake 12 c, and fourth fluid brake 12 d, are coupled by aninlet hose 16 c. The fluid channel of the port 31 a of theelectromagnetic valve 30 according to the present embodiment is closedoff.

On the other hand, a discharge port 29 b, which is a fluid channel, isprovided at the airtight spaces 28 communicating with the inlet ports 29a of the first fluid brake 12 a, second fluid brake 12 b, third fluidbrake 12 c, and fourth fluid brake 12 d.

One end of a vent hose 16 d making up the fluid channel is coupled tothe discharge port 29 b. The other end of the vent hose 16 d is coupledto a port 31 d of an electromagnetic valve 30A having a configurationgenerally the same as that of the electromagnetic valve 30.

Now, the relation is set such that the cross-sectional area Qx2 of theinlet hose 16 c is smaller than the cross-sectional area Qy2 of the venthose 16 d.

The electromagnetic valve 30A has, in addition to the port 31 d, a port31 e released to the atmosphere. The port 31 d and port 31 e of theelectromagnetic valve 30A are of a configuration controllable by acontrol circuit 35A.

The first switch 13 a and the second switch 13 b are electricallyconnected to the control circuit 35A. The control circuit 35A iselectrically connected to each of the electromagnetic valve 30 and theelectromagnetic valve 30A. In the present embodiment, the controlcircuit 35A, the electromagnetic valve 30 and the electromagnetic valve30A, and the inlet hose 16 c and the vent hose 16 d make up the fixingforce control means.

Now, the operation of the surgery equipment holding device configuredthus will be described.

First, the surgeon presses and operates the first switch 13 a and thesecond switch 13 b. As a result, at the control circuit 35A, the port 31c and port 31 b provided on the electromagnetic valve 30 are in acommunicating state, while the channel to the port 31 d of theelectromagnetic valve 30A is closed off. Accordingly, the pressuredfluid supplied from the fluid pressure source 15 passes through the hose16 b, electromagnetic valve 30, and inlet hose 16 c, and flows into theairtight space 28, thereby raising the internal pressure. Consequently,as with the first embodiment, the fixing force of the first fluid brake12 a, second fluid brake 12 b, third fluid brake 12 c, and fourth fluidbrake 12 d drop, attaining a fixation disengagement state.

Next, when the surgeon releases the first switch 13 a and the secondswitch 13 b, at the control circuit 35A, the port 31 a and port 31 b ofthe electromagnetic valve 30 are in a communicating state, while theport 31 d and port 31 e of the electromagnetic valve 30A are also in acommunicating state. At this time, the fluid channel to the port 31 c isclosed off.

Accordingly, the pressured fluid filling the airtight space 28 isreleased into the atmosphere via the vent hose 16 d, port 31 d, and port31 e. Consequently, as with the first embodiment, the first fluid brake12 a, second fluid brake 12 b, third fluid brake 12 c, and fourth fluidbrake 12 d are in a fixed state.

Now, the cross-sectional area of the inlet hose 16 c is set to besmaller than the cross-sectional area of the vent hose 16 d, so theamount of change in pressure of the airtight space 28 per time incrementis smaller at the time of disengaging the fluid brake fixation.Consequently, operations and advantages the same as those of the firstembodiment can be obtained.

In addition, with the present embodiment, a common fluid channel forpressured fluid to pass through at the fixation action time and thefixation disengagement action time is not configured. Accordingly, thechannel for pressured fluid at the fixation action time and the channelfor pressured fluid at the fixation disengagement action time areindependently configured. Accordingly, action control for each can beindependently designed and disposed, thereby realizing handy and easyhigh-precision control.

While the present embodiment is described with a configuration using aninlet hose 16 c, other configurations may be used, such as one with adiaphragm disposed instead of the inlet hose 16 c.

A third embodiment of the present invention will be described withreference to FIGS. 8 and 9.

Note that with the present embodiment, components common to theabove-described embodiments will be denoted with the same referencenumerals and description thereof will be omitted.

As shown in FIG. 8, with the present embodiment, mechanical switchesdenoted by reference numerals 50 a and 50 b are provided at theequipment holding portion 6. The mechanical switches 50 a and 50 b arefixation disengaging instructing means capable of mechanicallycontrolling the pressured fluid which is the acting energy of the firstfluid brake 12 a, second fluid brake 12 b, third fluid brake 12 c, andfourth fluid brake 12 d, which are fixation maintaining means. Themechanical switches 50 a and 50 b are disposed at axially symmetricalpositions as to the insertion axis 1 b of the endoscope 1.

As shown in FIG. 9, known mechanical valves, denoted by referencenumerals 51 and 52, are provided at the mechanical switches 50 a and 50b. These mechanical valves 51 and 52 are respectively joined to themechanical switches 50 a and 50 b which are manual push-button switchesintegrally joined to the axis 34 instead of the electromagnetic valve 30shown in FIG. 4A according to the first embodiment.

As with the electromagnetic valve 30 in the first embodiment, themechanical valves 51 and 52 have respective input ports 51 a and 52 a,discharge ports 51 b and 52 b, and functioning ports 51 c and 52 c.

Now, the operation of the mechanical valve 51 will be described. Notethat the action of the mechanical valve 52 is the same as the action ofthe mechanical valve 51. Accordingly, only the mechanical valve 51 willbe described here, and description of the mechanical valve 52 will beomitted.

The mechanical valve 51 is channel switching means, and normally, in thestate that the mechanical switch 50 a is not pressed, the discharge port51 b and the functioning port 51 c are in a communicating state. Whenthe mechanical switch 50 a is in a pressed state, the input port 51 aand the functioning port 51 c are in a communicating state.

A hose 55 extending from the fluid pressure source 15 is coupled to theinput port 51 a of the mechanical valve 51, such that the connection isairtight, while allowing the fluid to pass through. The functioning port51 c of the mechanical valve 51 and the input port 52 a of themechanical valve 52 are coupled via a hose 56, such that the connectionis airtight, while allowing the fluid to pass through.

Further, a hose 57 is coupled to the functioning port 52 c of themechanical valve 52, and each of the branched ends of the hose 57 areconnected to one end of directional diaphragm units 42 a, 42 b, 42 c,and 42 d, each having a configuration that same as the directionaldiaphragm unit 42 described in the first embodiment.

The other end of the directional diaphragm units 42 a, 42 b, 42 c, and42 d, and the airtight space 28 of the first fluid brake 12 a, secondfluid brake 12 b, third fluid brake 12 c, and fourth fluid brake 12 d,respectively communicate via hoses 58 a, 58 b, 58 c, and 58 d.

Note that both discharge ports 51 b and 52 b are opened to theatmosphere.

Also, the check valves 44 provided within the directional diaphragmunits 42 a, 42 b, 42 c, and 42 d are disposed so that the pressuredfluid within the airtight spaces 28 will pass.

Further, the diameter dimensions of diaphragms 43 a, 43 b, 43 c, and 43d, disposed within the directional diaphragm units 42 a, 42 b, 42 c, and42 d, are set such that the relation Φa<Φb<Φc<Φd holds.

With the present embodiment, the directional diaphragm units 42 a, 42 b,42 c, and 42 d, and the mechanical valves 51 and 52 make up the fluidcontrol unit 53 serving as the fixation force control means.

The operation of the surgery equipment holding device configured asdescribed above will now be described.

First, description will be made regarding a case of the surgeon movingthe endoscope 1.

In the event that the surgeon operates the mechanical switch 50 a, theinput port 51 a and the functioning port 51 c are placed in acommunicating state at the mechanical valve 51. Also, in the event thatthe surgeon operates the mechanical switch 50 b, the input port 52 a andthe functioning port 52 c are placed in a communicating state at themechanical valve 52.

In the event that the surgeon operates both the mechanical switch 50 aand the mechanical switch 50 b simultaneously, the pressured fluid fromthe fluid pressure source 15 passes through the hose 55, input port 51a, functioning port 51 c, hose 56, input port 52 a, and functioning port52 c, in that order, and flows into the hose 57. The pressured fluidwhich has flowed into the hose 57 flows into the airtight space 28 ofthe first fluid brake 12 a, second fluid brake 12 b, third fluid brake12 c, and fourth fluid brake 12 d, via the directional diaphragm units42 a, 42 b, 42 c, and 42 d which are disposed in parallel on the hose57.

Now, the relation of the moment Ma, Mb, Mc, and Md, as to the loadnecessary for holding the endoscope, with regard to the first fluidbrake 12 a, second fluid brake 12 b, third fluid brake 12 c, and fourthfluid brake 12 d, is Ma>Mb>Mc>Md.

That is to say, the moment Md placed on the fulcrum A within the fourthfluid brake 12 d is the load from the third arm 10 c to the endoscope 1.In comparison, the moment Mc placed on the fulcrum A within the thirdfluid brake 12 c is the load from the rod 11 b to the endoscope 1. Also,the moment Mb placed on the fulcrum A within the second fluid brake 12 bis the load from the second arm 10 b to the endoscope 1, and the momentMa placed on the fulcrum A within the first fluid brake 12 a is the loadfrom the rod 11 a to the endoscope 1.

On the other hand, the relation Φa<Φb<Φc<Φd holds for the diaphragms 43a, 43 b, 43 c, and 43 d, with the channel cross-sectional areas beingadjusted according to the moment Ma, Mb, Mc, and Md relating to thefirst fluid brake 12 a, second fluid brake 12 b, third fluid brake 12 c,and fourth fluid brake 12 d, so as to act such that the first fluidbrake 12 a, second fluid brake 12 b, third fluid brake 12 c, and fourthfluid brake 12 d all are disengaged simultaneously and at the samespeed.

Next, description will be made regarding a case of the surgeon fixingthe endoscope 1.

When the surgeon releases the mechanical switches 50 a and 50 b, as withthe first embodiment, the first fluid brake 12 a, second fluid brake 12b, third fluid brake 12 c, and fourth fluid brake 12 d are immediatelyplaced in a fixed state.

That is to say, the fixation disengaging action of the surgery equipmentholding device is carried out gradually, while the fixing action of thesurgery equipment holding device is performed rapidly. Thus, at the timeof disengaging, the fixed state of the endoscope can be disengagedwithout applying a sudden holding load on the hand of the surgeon, whileon the other hand, the endoscope 1 can be rapidly fixed at the time offixing.

Thus, with the present embodiment, no electrical control is usedwhatsoever, so the configuration can be made even more simple.

Also, the fixation disengaging speed can be set to be differentaccording to the difference of moment relating to the fluid brakes, soan even more operable surgery equipment holding device can be provided,by arranging the fixation of the joints to be disengaged at the samespeed as to the holding hand of the surgeon.

Further, the mechanical switches are disposed axially symmetrical as tothe insertion axis of the endoscope, resulting in a form where thesurgeon grasps the endoscope itself. Accordingly, the surgeon can graspthe position on the endoscope even more easily than with the firstembodiment.

Accordingly, the problem of fatigue on the surgeon, which is caused bydifference in operability wherein the relative positional relationbetween the switches and the surgery equipment differs from one surgicaltherapeutic device to another, can be lessened.

A fourth embodiment of the present invention will be now described withreference to FIGS. 10 to 12B.

Note that with the present embodiment, components common to theabove-described embodiments will be denoted with the same referencenumerals and description thereof will be omitted.

As shown in FIG. 10, the grasping portion 7 according to the presentembodiment is configured of a holding member 61 and rotating member 60.The holding member 61 is connected and fixed to the third arm 10 c. Therotating member 60 has a configuration rotatably attached to the holdingmember 61.

As shown in FIG. 11, the rotating member 60 has a pipe-shaped form. Therotating member 60 is fit in between cylindrical protrusion 61 a and 61b of the holding member 61, and rotates freely with respect to theinsertion axis 1 b of the endoscope 1.

A first switch 13 a and second switch 13 b are provided at axiallysymmetrical positions as to the axis 1 b of the endoscope 1, on theperimeter of the rotating member 60. The first switch 13 a and secondswitch 13 b are connected to a later-described fluid control unitdenoted by reference numeral 63 in FIG. 12A, serving as fixing forcecontrol means.

As shown in FIG. 12A, the fluid control unit 63 comprises a controlcircuit 62, a first electromagnetic valve 67 and second electromagneticvalve 68 similar to the electromagnetic valve 30 in the firstembodiment, and a fluid transmission delay unit 64.

The first switch 13 a and second switch 13 b are electrically connectedto the electromagnetic valves 67 and 68 respectively via the controlcircuit 62. The fluid transmission delay unit 64 comprises ports 64 aand 64 b which are inlet/outlets for the fluid, with a long hose 65 ofwhich tube length is long coupled. The long hose 65 is airtight andcapable of passing fluid between the ports 64 a and 64 b.

The tube length of the hose 65 is set to that capable of exhibiting thelater-described operations in comparison with the above-described hose16 b, specifically.

The fluid pressure source 15 is coupled via the hose 16 a to the inputport 66 of the fluid control unit 63, such that the connection isairtight, while allowing the fluid to pass through. The input port 66and the input port 67 a of the first electromagnetic valve 67 arecoupled such that the connection is airtight, while allowing the fluidto pass through. The functional port 67 c of the first electromagneticvalve 67 and the port 64 a of the fluid transmission delay unit 64 arecoupled such that the connection is airtight, while allowing the fluidto pass through.

Also, the port 64 b of the fluid transmission delay unit 64 and theinput port 68 a of the second electromagnetic valve 68 are coupled suchthat the connection is airtight, while allowing the fluid to passthrough. Moreover, the functional port 68 c of the secondelectromagnetic valve 68 and the hose 16 b are coupled such that theconnection is airtight, while allowing the fluid to pass through.

The branched base of the hose 16 b is coupled in parallel to the inletport 29 of the airtight space 28 formed at the first fluid brake 12 a,second fluid brake 12 b, third fluid brake 12 c, and fourth fluid brake12 d, such that the connection is airtight, while allowing the fluid topass through. Also, the discharge ports 67 b and 68 b of theelectromagnetic valves 67 and 68 are opened to the atmosphere.

The operation of the surgery equipment holding device thus configuredwill now be described.

In the state that the surgeon has not pressed the first switch 13 a andsecond switch 13 b, the functional port 67 c and discharge port 67 b ofthe electromagnetic valve 67, and the functional port 68 c and dischargeport 68 b of the electromagnetic valve 68 communicate. Accordingly, theairtight space 28 within the first fluid brake 12 a, second fluid brake12 b, third fluid brake 12 c, and fourth fluid brake 12 d, and theinterior of the hose 65 of the fluid transmission delay unit 64, areopened to the atmosphere. Thus, as with the first embodiment, the firstfluid brake 12 a, second fluid brake 12 b, third fluid brake 12 c, andfourth fluid brake 12 d, are in a fixed state.

In the event of moving the endoscope 1, the surgeon presses and operatesthe first switch 13 a and second switch 13 b. This causes theelectromagnetic valves 67 and 68 within the fluid control unit 63 tooperate in the same manner as with the first embodiment, via the controlcircuit 62. That is to say, the input port 67 a and the functional port67 c of the electromagnetic valve 67 communicate, and the input port 68a and the functional port 68 c of the electromagnetic valve 68communicate.

Thus, the pressured fluid starts to flow in from the fluid pressuresource 15. The pressured fluid then passes through the hose 65 disposedat the fluid transmission delay unit 64, and increases the pressureinside the airtight space 28 within the first fluid brake 12 a, secondfluid brake 12 b, third fluid brake 12 c, and fourth fluid brake 12 d.As a result of this, the first fluid brake 12 a, second fluid brake 12b, third fluid brake 12 c, and fourth fluid brake 12 d attain a fixationdisengaged state, as with the first embodiment.

Then, when the surgeon releases the first switch 13 a and the secondswitch 13 b to fix the endoscope 1, the first switch 13 a and the secondswitch 13 b make transition to the original state before being operated.

Consequently, the pressured fluid filling the airtight space 28 isdischarged into the atmosphere from the discharge port 68 b of thesecond electromagnetic valve 68. On the other hand, the pressured fluidfilling the hose 65 of the fluid transmission delay unit 64 isdischarged into the atmosphere from the discharge port 67 b of the firstelectromagnetic valve 67.

That is to say, the pressured fluid within the airtight space 28 mustpass through the hose 65 of the fluid transmission delay unit 64 in theevent that the surgeon moves the endoscope 1, but does not pass throughthe hose 65 in the event that the surgeon fixes the endoscope 1.

Accordingly, the longer the hose 65 is, the longer the time required forthe pressured fluid to pass through the hose 65. Thus, when comparingthe amount of change in pressure in the airtight space 28 per timeincrement for the first fluid brake 12 a, second fluid brake 12 b, thirdfluid brake 12 c, and fourth fluid brake 12 d to make transition to thedisengaged state or the fixed state from the time of pressing orreleasing the first switch 13 a and the second switch 13 b, the amountof change in pressure is clearly smaller at the time of disengaging thefixation than at the time to the fixed state.

This means that, as with the above-described embodiments, thedisengaging action of the surgery equipment holding device can becarried out gradually, while the fixing action of the surgery equipmentholding device can be performed rapidly.

Also, providing the switches at axially symmetrical positions as to theinsertion axis of the endoscope obtains the same operations as with thethird embodiment. Further, with the present embodiment, the switches arerotatable with respect to the insertion axis of the endoscope, so in theevent that the position is such that the surgeon cannot readily pressthe switches, rotating the rotating member allows rotation with therelative positional relation maintained between the switches and theendoscope. Thus, the surgeon can change the position of the switches toan easily-operated position, thereby reducing fatigue of the surgeon andimproving the efficiency of the surgery.

Also, though the present embodiment has been described with aconfiguration using a hose for the fluid transmission delay unit, thesame operations and advantages can be obtained with other arrangements,such as replacing the fluid transmission delay unit with a containersuch as a chamber 100 shown in FIG. 12B, or the diaphragm 39 andvariable diaphragm 39 a shown in FIGS. 4A and 4B.

A fifth embodiment of the present invention will be now described withreference to FIGS. 13 to 14B.

The configuration of the present embodiment is an arrangement whereinthe control unit of the second embodiment disclosed in JapaneseUnexamined Patent Application Publication No. 07-227398 mentioned aboveas conventional art is replaced with a later-described control circuit70.

As shown in FIG. 13, the surgery equipment holding device compriseselectromagnetic brakes 71, 72, and 73, and counterweights 74 and 75. Inthe event that the fixation state of the joints disposed on the armportion is disengaged, the endoscope 1 maintains a balanced state by thecounterweights 74 and 75.

As shown in FIG. 14A, the control circuit 70 serving as fixing forcecontrol means in the present embodiment is electrically connected anddisposed between a switch 77 and the electromagnetic brakes 71, 72, and73.

The functional configuration of the control circuit 70 is such that, inthe event that the switch 77 is pressed, the voltage increases as to theelectromagnetic brakes 71, 72, and 73, at a predetermined voltageincrease per time increment, dE (V/sec). On the other hand, in the eventthat the switch 77 is turned off, the voltage decreases at apredetermined voltage decrease dEs (V/sec).

The present embodiment sets the relation dE≦dEs between dE and dEs inthe present embodiment, so as to effect control.

Further, with the present embodiment, in the event that the switch 77 isnot operated, the electromagnetic brakes 71, 72, and 73 are fixed by amagnetic force P0 due to a permanent magnet 78 as shown in FIG. 14B.

Upon the surgeon grasping the grasping portion of the endoscope andpressing the switch 77, voltage is applied to the electromagnetic brakes71, 72, and 73 increasing by dE (V/sec). Accordingly, the fixation stateis gradually disengaged.

Then, when the surgeon releases the switch 77, the control circuit 70immediately shuts off electric power supply to the electromagneticbrakes 71, 72, and 73. Subsequently, the voltage is decreased by dEs(V/sec) per time increment.

In other words, with the control circuit 70, the electromagnetic brakesgradually operate to disengage the fixing force thereof in the eventthat the surgeon presses the switch 77 to move the endoscope 1, due tothe setting of the relation dE≦dEs between the amount of voltageincrease and the amount of voltage decrease. Thus, the same operationsand advantages as with the above embodiments can be obtained.

Accordingly, with the present embodiment, the desired operations andadvantages can be easily realized by adding this control circuit to thesurgery equipment holding device using known electromagnetic brakes.

Also, situations wherein force of the hand of the surgeon is suddenlyapplied to the surgery equipment holding device at the time ofdisengaging braking, which may occur even with balanced surgeryequipment holding devices, can be avoided with the present embodiment,meaning that the surgeon can perform fixation disengaging operation ofthe surgery equipment without losing sight of the part to be treated orobserved with the surgery equipment, and also can quickly perform fixingoperations, as well.

Now, FIG. 15 is a diagram explaining a modification of the fifthembodiment. As shown in FIG. 15, with the present embodiment, motorbrakes 90 are used instead of the electromagnetic brakes 71, 72, and 73in the fifth embodiment.

The motor brakes denoted by reference numeral 90 in the figure are motorbrakes using known motors, and in the present embodiment the motorbrakes 90 are disposed instead of the electromagnetic brakes 71, 72, and73 in FIG. 13.

Here, description will be made regarding the motor brake 90 disposed ata lock of a swinging rod 81, and description of the remaining motorbrakes will be omitted since the configuration thereof is the same.

A cover 80 is rotatably disposed so as to rotate on a rotating axis O2as the axis thereof, by bearings 91 a and 91 b disposed on a supportingmember 79 disposed on the upper part of a vertical rod 82. The lower endof the swinging rod 81 is linked to the cover 80.

Reference numeral 92 denotes a motor, which is electrically connected tothe switch 77 via the control circuit 70. The motor 92 is integrallyfixed to an internal tube 94 by a screw 93. Also, the internal tube 94and the supporting member 79 are integrally fixed by a screw 95.

An operating screw 97 is rotatably disposed by bearings 96 a and 96 bwithin an internal tube 94. This operating screw 97 is integrally joinedto a rotational output shaft 92 a of the motor 92.

At the time of disengaging fixation, the control circuit 70 runs themotor 92 at a rotation speed R (rpm), and at the time of fixing, runsthe motor 92 at a rotation speed Rs (rpm). The present embodiment setsthe relation of R<<Rs between the rotation speed R and the rotationspeed Rs, thereby effecting control.

Also, reference numeral 98 denotes a lock nut, wherein female threadsfor screwing the operating screw 97 to are formed on the inner face ofthe lock nut 98, and a spline 98 a is formed on the perimeter facethereof.

A spline 79 a capable of sliding with the spline 98 a is formed on theend of the internal circumference of the supporting member 79 at thecover 80 side. Thus, rotation of the lock nut 98 in the direction ofrotating around the rotational axis O2 is suppressed, while beingslidable parallel to the rotational axis O2.

Reference numeral 98 b denotes a pressing portion for pressing theinternal face of the cover 80, that has been formed on the end of thelock nut 98.

Now, the operation of the surgery equipment holding device will bedescribed, including the operations of the motor brake.

In the state that the cover 80 and the supporting member 79 are pressedand fixed by the pressing portion 98 b formed on the end of the lock nut98, the surgeon pressing the switch 77 causes the control circuit 70 torun the motor 92. The resultant rotating action of the rotating outputshaft 92 a starts rotation of the operating screw 97 which has beenjoined to the rotating output shaft 92 a and is screwed to the lock nut98.

At this time, the rotation of the lock nut 98 is suppressed by thespline 98 a and 79 a. Accordingly, the lock nut 98 moves parallel to therotational axis O2 in the direction of the arrow, and disengages thepressed state by the pressing portion 98 b. As a result, the cover 80and the supporting member 79 become rotatable on the rotational axis O2.

Subsequently, in the event that the surgeon releases the switch 77, thecontrol circuit 70 starts the motor 92 rotating in the directionopposite to that described above. Accordingly, action opposite to thatdescribed above causes the lock nut 98 to move parallel to therotational axis O2 in the direction opposite to that described above, sothat the pressing portion 98 b is in the pressing state again, and thecover 80 and the supporting member 79 are in the fixing state again.

Now, the rotation of the motor 92 is made by the control circuit 70 tobe slower when fixation is disengaged as compared to when fixed, so theaction of disengaging the surgery equipment that is held can be carriedout gradually, while the fixing action can be performed rapidly, so thesurgeon can work without losing sight of the part to be treated orobserved with the surgery equipment

In this way, according to the present configuration, the control of thefixing force is control of only the rotation speed of the motor, soelectrical control can be performed even more easily.

Having described the preferred embodiments of the invention referring tothe accompanying drawings, it should be understood that the presentinvention is not limited to those precise embodiments and variouschanges and modifications thereof could be made by one skilled in theart without departing from the spirit or scope of the invention asdefined in the appended claims.

1. A surgery equipment holding device, comprising: means for holdingsurgery equipment, capable of changing the direction of surgeryequipment being held; means for maintaining the fixation force of themeans for holding at a predetermined value; means for disengaging thefixation force of the means for maintaining; and means for changing thefixation force of the means for maintaining over time, based oninstructions from the means for disengaging, wherein the means forchanging controls the amount of change of the fixation force per timeincrement in the fixation disengaging operation of the means formaintaining to be smaller than the amount of change of the fixationforce per time increment in the fixation operation of the means formaintaining, so that the disengaging operation of the surgery equipmentholding device is performed gradually, and the fixing operation of thesurgery equipment holding device is performed speedily, wherein themeans for maintaining comprises electromagnetic brakes for fixing bypressing with a member, and lowering the pressing force of the member byincreasing a voltage to the electromagnetic brakes; and wherein themeans for changing comprises a control circuit for controllingsequentially the driving electrical current output to theelectromagnetic brakes.
 2. The surgery equipment holding deviceaccording to claim 1, wherein the means for changing performs fixationdisengaging only in the event that two or more fixation disengaginginstructions are given from the means for disengaging.
 3. The surgeryequipment holding device according to claim 1, wherein, in the eventthat the means for maintaining comprises a fluid brake operated bypressured fluid supplied from a pressure source, the means for changingcomprises flow control means for controlling the flow per unit time atan inlet channel where the pressured fluid flows into the fluid brake tobe smaller than the flow per unit time at an discharge channel where thepressured fluid is discharged from the fluid brake.